/Engine/Source/Runtime/AnimGraphRuntime/Public/CommonAnimationLibrary.h
This function performs retargeting of rotation using an easing function. For this a range of motion needs to be defined as a euler angle, swing angle or twist
namespace CommonAnimationLibrary { FQuat CommonAnimationLibrary::RetargetSingleRotation ( const FQuat & Rotation, const FTransform & Source, const FTransform & Target, const [FRuntimeFloatCurve](API\Runtime\Engine\Curves\FRuntimeFloatCurve) & CustomCurve, EEasingFuncType EasingType, bool bFlipEasing, float EasingWeight, ERotationComponent RotationComponent, FVector TwistAxis, bool bUseAbsoluteAngle, float SourceMinimum, float SourceMaximum, float TargetMinimum, float TargetMaximum ) }